Problem: Simplify the following expression: $x = \dfrac{10}{4y} \div \dfrac{2}{5y}$
Answer: Dividing by an expression is the same as multiplying by its inverse. $x = \dfrac{10}{4y} \times \dfrac{5y}{2}$ When multiplying fractions, we multiply the numerators and the denominators. $x = \dfrac{ 10 \times 5y } { 4y \times 2}$ $x = \dfrac{50y}{8y}$ Simplify: $x = \dfrac{25}{4}$